Contact rolling bearing elements come in a variety of different shapes, including spherical, cylindrical and conical (taper roller). The running performance and noise generation of bearings is to a large extent dependent on the precision of the rolling elements. Typically the surface finish characteristics of rolling elements has a greater effect on the noise generated by a bearing than the surface finish of the tracks.
The form and surface finish of rolling elements is critical to the running performance and noise characteristics of any contact roller bearing. Taylor Hobson have a range of Form Talysurf systems which are suitable for measuring the form and surface finish characteristics of rolling elements. For details see the Form Talysurf links below. Also of critical importance is the roundness and waviness of the rolling elements. Typically these features are measured using roundness instruments the link below for more information.
Taylor Hobson have also developed a special fixturing device called a ball unit which can used with any Form Talysurf Inductive system to measure the surface finish of cylindrical and ball rolling elements. It works by using a friction pad to rotate a rolling element over a stationary inverted inductive gauge. The gauge range used is very small so the inductive gauge can be set to a high resolution setting and as such it can achieve very low surface finish measurements (<6nm Ra is feasible).